There is a very popular type of watercraft known as a "personal watercraft" which is designed to be operated primarily by a single rider. Although this type of watercraft is commonly employed for single riders, frequently provisions are made for accommodating additional passengers although the maximum number of passengers is more limited than conventional types of watercraft.
This type of watercraft is also generally quite sporting in nature and normally accommodates at least the rider on a type of seat in which the rider sits in a straddle fashion. The passenger's area is frequently open through the rear of the watercraft so as to facilitate entry an exit of the rider and passengers to the body of water in which the watercraft is operating as this type of watercraft is normally employed with passengers that are wearing swimming suits.
These personal watercraft are generally quite small so that they can be conveniently transported from the owner's home to a body of water for its use. Because of the small size, the layout of the components is extremely critical and this gives rise to several design considerations that are peculiar to this type of watercraft. However, due to the sporting nature it is also desirable if the watercraft can be powered by an engine and propulsion device that have high powers and efficiency.
Normally this type of watercraft has been powered by an inline type of engine. However, in order to improve the performance of the engine it is desirable to increase the number of cylinders in the engine. With inline engines, the use of more than three cylinders can give rise to considerable space requirements due to the elongation of the engine. Although V-type engines are more compact in some regards, the angle between the cylinder banks give these engines a substantial degree of width. This itself presents certain problems in locating the engine, particularly in conjunction with a small personal type watercraft.
It is, therefore, a principal object of this invention to provide an improved personal watercraft that is powered by a V-type engine.
It is a further object of this invention to provide a small watercraft of the type having a seat in which the rider is seated in a straddle fashion and which can be powered by a V-type of engine.
In watercraft of the type already described, because of the small nature of the watercraft it is extremely important to provide good balance under all conditions. This is particularly true when the watercraft is designed so as to accommodate more than one passenger. One-way in which balance has been obtained is to try to concentrate all of the heavier objects of the watercraft on its longitudinal centerline. However, this gives rise to problems in fore and aft weight distribution and also can present spatial difficulties particularly when using a straddle-type seating arrangement.
It is, therefore, a still further object of this invention to provide an improved component of layout for a small watercraft.
It is a further object of this invention to provide a fuel tank arrangement for a personal watercraft that will assist in maintaining balance under all conditions or substantially all conditions and which will still afford a large fuel capacity.
As has already been noted, these personal watercraft normally employ straddle-type seats that will accommodate one or more passengers. However, if more than three passengers are to be accommodated, then the tandem-type seat can dictate a larger size for the watercraft than is desired. However, side-by-side seating also is not particularly desirable with this type of watercraft as it may unduly increase the width of the hull and diminish its performance. In addition, there are advantages to having the rider sit in a straddle fashion as it permits his center of gravity to be raised and he can facilitate the handling of the watercraft by leaning the hull when maneuvering.
It is, therefore, a still further of this invention to provide an improved seating arrangement for a personal watercraft that will permit the use of a straddle-type seat for the rider but which will also afford additional seating for added passengers without increasing the length of the watercraft.
It is a further object of this invention to provide an improved seating arrangement for this type of watercraft.
It should be readily apparent from the foregoing description that personal watercraft of the type described tend to be extremely compact and spartan in nature. However, there are numerous occasions when the rider or passengers may wish to carry with them additional objects. However, due to the sporting nature of this type of watercraft, the objects cannot be easily carried within the passenger compartment. However, the compact nature of the hull and the provision for the propulsion device powering engine and engine accessories does not afford significant storage areas within the hull.
It is, therefore, a still further object of this invention to provide an improved personal watercraft hull configuration that will permit a compact nature and still afford one or more storage compartments.
It is a further object of this invention to provide an improved storage compartment configuration for a personal watercraft wherein the storage compartment makes use of space otherwise wasted in the watercraft.
The type of personal watercraft which has been described herein is frequently powered by a jet propulsion unit which jet propulsion unit is positioned at least in part within a tunnel formed at the rear of the underside of the hull of the watercraft. This affords a very neat appearance but adds to the difficulties in providing a compact construction which will accommodate all of the needs aforenoted.
The jet propulsion unit includes an impeller that is driven by an impeller shaft that extends forwardly through the tunnel and through a bulkhead formed at the front of the tunnel for connection to the internally mounted powering engine of the hull. However, in order to improve weight balance and to provide more usable space, frequently it is desirable to position the engine at a point well forward of the forward bulkhead of the tunnel. This gives rise to long, unsupported shafts.
It is, therefore, a still further of this invention to provide an improved driving arrangement for a jet propulsion unit of a personal watercraft.
It is a further object of this invention to provide an improved bearing arrangement for the drive shaft of a jet propelled personal watercraft that affords adequate bearing support throughout the length of the driving arrangement.
As has been noted, the personal watercraft of the type which have been described are quite sporting in their nature. In fact, it is not uncommon for this type of watercraft to occasionally capsize. As with all watercraft, this can present some particular problem, particularly with the engine and its exhaust system. It is normally the practice in watercraft to discharge the exhaust gases from the engine either into the atmosphere through the body of water in which the watercraft is operating or at a point quite close to the water level. Hence, extreme alterations in the hull orientation can cause water easily to flow through the exhaust system to the engine. In addition, it is often the practice to discharge the cooling water from the engine back to the body of water in which the watercraft is operating through its exhaust system. This gives rise to further possibilities for water to flow to the engine through the exhaust system under abrupt changes in hull attitude.
It is, therefore, a still further object of this invention to provide an improved exhaust system for a watercraft in which the configuration is such so as to discourage water from flowing to the engine through the exhaust system if the hull changes its attitude.
It is a further object of this invention to provide an improved exhaust system for a personal watercraft wherein the exhaust system is configured to reduce the likelihood of water reaching the engine through the exhaust system, even if the watercraft becomes capsized.
In watercraft that incorporate multiple cylinders there are some advantages in employing separate exhaust pipes for groups of cylinders to achieve desired exhaust tuning. In addition, if the engine is disposed so that it has the cylinders arranged in angularly related banks, it is quite common practice to employ separate exhaust systems for each bank of cylinders. This gives rise to further problems in connection with assuring that water will not flow to the engine through the exhaust system, particularly if the watercraft is either capsized or has its orientation significantly altered from the normal operation orientation.
It is, therefore, a still further object of this invention to provide an improved watercraft system for a watercraft powered by a V-type engine.
In order to protect the engine from ingesting water through the exhaust system, it is a common practice to provide a water trap device in the exhaust conduit which discharges the exhaust gases from the engine exhaust ports to the atmosphere. These water trap devices are designed not only to separate water from the exhaust gases when the water is discharged from the engine cooling system through the exhaust system but also to ensure that water which may enter the exhaust pipes may be trapped before it can reach the exhaust port.
In order to be effective, these water trap devices must have some significant volume and this additionally places further problems on the designer in laying out all components of the personal type of watercraft.
It is, therefore, a still further object of this invention to provide an improved water trap arrangement for a personal watercraft.
It is a further object of this invention to provide an improved component layout for a personal watercraft wherein the components including the water trap are located so as to provide a stable center of gravity for the watercraft under all conditions.
In order to permit the components for the watercraft including the water trap device to be located to maintain the desired balance for the hull, this frequently can dictate the positioning of the water trap device in a location where the exhaust gases would not normally pass. For example, it may be desirable to position the water trap device in the front of the engine even though the exhaust gases are discharged rearwardly. This gives rise to additional problems in locating all of the components including the exhaust conduitry to have the exhaust gases flow forwardly to the water trap and then rearwardly for discharge.
It is, therefore, a still further object of this invention to provide improved component layout and exhaust system for a watercraft wherein the water trap device may be positioned in a location where the exhaust gases would not normally flow and the exhaust conduitry can deliver the exhaust gases in the desired flow path without encroaching on other components of the watercraft.
As has been previously noted, the personal watercraft of the type described are sporting in nature and frequently the rider and/or passenger may wish to exit the watercraft to enter the body of water in which the watercraft is operating or to enter the watercraft of the body of water in which the watercraft is operating. Frequently, the riders compartment is positioned to the rear of the hull and opens through he rear of the hull to facilitate such reentry. However, to assure ease of entry it is desirable that the rear portion of the watercraft be relatively low to be accessible from the body of water in which the watercraft is operating. This means that any rearwardly positioned seats if they have seat backs will interfere with such entry. However, it is also desirable, particularly for a rearwardly seated passenger to have a backrest so as to provide comfort and some degree of security. However, a backrest can make reentry of the watercraft difficult, as should be readily apparent.
It is, therefore, a still further object of this invention to provide an improved backrest arrangement for the rear seat of a personal watercraft which can be moved to facilitate reentry.
It is a further object of this invention to provide a rear seat back for the rear seat of a personal watercraft which can also function as a boarding ladder so as to move the seat back out of the way and for entry and also to assist in entry.
It should be readily apparent from the foregoing description that the small personal watercraft of the type described present a number of problems in accommodating passengers and laying out of the various components. One thing that may be desirable with this type of watercraft is to provide a forward deck area on which riders may lie for sunbathing or the like. Of course, because of the extremely short desirable length for such watercraft, this is not always feasible.
It is, therefore, a still further object of this invention to provide a hull configuration for a small watercraft wherein the deck area may be used by a rider for sunbathing.